netvirt/renderers/neutron/src/main/java/org/opendaylight/netvirt/netvirt/renderers/neutron/DelegatingDataTreeListener.java

   1 /*
   2  * Copyright (c) 2013, 2016 Red Hat, Inc. and others. All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.netvirt.netvirt.renderers.neutron;
  10
  11 import com.google.common.base.Preconditions;
  12 import java.util.Collection;
  13 import java.util.concurrent.ExecutorService;
  14 import java.util.concurrent.Executors;
  15 import java.util.concurrent.ThreadFactory;
  16 import javax.annotation.Nonnull;
  17
  18 import com.google.common.util.concurrent.ThreadFactoryBuilder;
  19 import org.opendaylight.controller.md.sal.binding.api.*;
  20 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  21 import org.opendaylight.yangtools.yang.binding.DataObject;
  22 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
  23 import org.slf4j.Logger;
  24 import org.slf4j.LoggerFactory;
  25
  26 /**
  27  * Data-tree listener which delegates data processing to a {@link DataProcessor}.
  28  */
  29 public class DelegatingDataTreeListener<T extends DataObject> implements AutoCloseable, ClusteredDataTreeChangeListener<T> {
  30     private static final Logger LOG = LoggerFactory.getLogger(DelegatingDataTreeListener.class);
  31     protected DataBroker db;
  32     private static final ThreadFactory threadFactory = new ThreadFactoryBuilder()
  33         .setNameFormat("NV-NeutronDTL-%d").build();
  34     private final ExecutorService executorService = Executors.newFixedThreadPool(1, threadFactory);
  35     private final DataProcessor<T> dataProcessor;
  36     private ListenerRegistration<DelegatingDataTreeListener<T>> listenerRegistration;
  37
  38     public DelegatingDataTreeListener(DataProcessor<T> dataProcessor,
  39                                       DataBroker db, DataTreeIdentifier<T> treeId) {
  40         this.dataProcessor = Preconditions.checkNotNull(dataProcessor, "Data processor can not be null!");
  41         registerListener(Preconditions.checkNotNull(db, "Data broker can not be null!"),
  42                 Preconditions.checkNotNull(treeId, "Tree identifier can not be null!"));
  43     }
  44
  45     private void registerListener(final DataBroker db, DataTreeIdentifier<T> treeId) {
  46         try {
  47             LOG.info("Registering Data Change Listener for {}", getClass().getSimpleName());
  48             this.db = db;
  49             listenerRegistration = db.registerDataTreeChangeListener(treeId, this);
  50         } catch (final Exception e) {
  51             LOG.warn("{} DataChange listener registration fail!", getClass().getSimpleName(), e);
  52             throw new IllegalStateException("DataTreeListener startup fail! System needs restart.", e);
  53         }
  54     }
  55
  56     private void processChanges(Collection<DataTreeModification<T>> changes) {
  57         for (DataTreeModification<T> change : changes) {
  58             final InstanceIdentifier<T> key = change.getRootPath().getRootIdentifier();
  59             final DataObjectModification<T> mod = change.getRootNode();
  60             switch (mod.getModificationType()) {
  61                 case DELETE:
  62                     dataProcessor.remove(key, mod.getDataBefore());
  63                     break;
  64                 case SUBTREE_MODIFIED:
  65                     dataProcessor.update(key, mod.getDataBefore(), mod.getDataAfter());
  66                     break;
  67                 case WRITE:
  68                     if (mod.getDataBefore() == null) {
  69                         dataProcessor.add(key, mod.getDataAfter());
  70                     } else {
  71                         dataProcessor.update(key, mod.getDataBefore(), mod.getDataAfter());
  72                     }
  73                     break;
  74                 default:
  75                     throw new IllegalArgumentException("Unhandled modification type " + mod.getModificationType());
  76             }
  77         }
  78     }
  79
  80     @Override
  81     public void onDataTreeChanged(@Nonnull final Collection<DataTreeModification<T>> changes) {
  82         Preconditions.checkNotNull(changes, "Changes may not be null!");
  83         executorService.submit(new Runnable() {
  84             @Override
  85             public void run() {
  86                 processChanges(changes);
  87             }
  88         });
  89     }
  90
  91     @Override
  92     public void close() {
  93         if (listenerRegistration != null) {
  94             listenerRegistration.close();
  95             listenerRegistration = null;
  96         }
  97     }
  98 }